Right country, wrong analysis: I am writing from Scotland, which is the right place to be if you want a good perspective on the increasingly bitter AV row. In one of the more incendiary arguments, Lord Forsyth, who was one of Margaret Thatcher's most devoted ministers, has argued that the Scots may tilt the referendum in favour of changing the voting system.

More of them will vote in the referendum because 5 May is also the date of the Scottish parliamentary elections, and the Scots are more left-leaning, and are used to different electoral systems. In Forsyth's view this would be an outrage, rigging the outcome, which would inflame English hostility to the Scots. There is muttering, yet again, about the union being in danger.

With all respect to the peer, the notion that you shouldn't hold a referendum on the obvious date, the one when people across the UK are voting in local elections, in case more Scots turn up, is ludicrous. The Scottish experience is important in another way. Up here the Liberal Democrats and Labour are playing vigorous footsie under the table. If Iain Gray, the Scottish Labour leader, beats Alex Salmond's Scottish Nationalists for first place in the elections for the Scottish parliament, he would try to do a deal with the Scottish Lib Dems rather than running a minority administration.

It might not happen: the SNP are formidable fighters and could well keep Labour out. But think of the implications if it did. Nick Clegg and David Cameron would be governing together at Westminster, routinely attacking and jeering at Labour in the Commons; while in Edinburgh, Clegg's Scottish colleagues would be sitting alongside Labour ministers and presumably slagging off the Conservatives.

That would be interesting. Scotland matters a lot to the whole philosophy of fairer votes and coalitions: it was here the first such deals were made in recent times. Scotland is also particularly important in the modern development of the Lib Dems. In Scotland, leaders such as Menzies Campbell and David Steel had good relationships with former Labour people such as John Smith and Donald Dewar: they all considered themselves part of a wider anti-Conservative movement. This warmth transmitted itself to a later generation, including Charles Kennedy.

So tying the knot in Scotland would deepen the heart-searching among Lib Dems over their collusion with Cameron's Tories. It would follow shortly after Vince Cable's fascinating decision to distance himself from the prime minister over immigration – not his first calculated slight to the coalition atmosphere – and from resurgent rumours that Tim Farron, the Lib Dem president, might be used to spearhead a rebellion against Clegg. (He denies it, but doesn't deny he was approached by Labour.)

Ed Miliband may be over-optimistic when he lets it be known that a Scottish Lib-Lab coalition could be a wedge that breaks the Westminster coalition and brings down the government. But stranger things have happened: everything now depends on the mood in the weeks after 5 May.

This takes us to the AV referendum itself. Never has a duller issue caused so many apparently normal people to sound almost insane with rage. Apart from Forsyth's warnings over a "rigged" result, we have had George Osborne attacking the idea that the Electoral Reform Society is using its money to campaign for electoral reform; accusations of racism and smears – through the use of Nick Griffin's photo by the pro-AV team – and Chris Huhne describing his Tory colleague Baroness Warsi as descending to "the politics of the gutter". In the Observer on Sunday, Paddy Ashdown counter-attacked, calling Osborne's remarks about the ERS bizarre and stinking.

Given that AV is a relatively minor shift in voting whose effects are unknowable but would certainly not alter the map of British politics, why are they all so upset? Because if the AV vote is lost Clegg's position in the Lib Dem family would dramatically worsen, and the odds of a revolt against him sharply increase. But if the vote is won, Tory rightwingers, who already see Cameron as a closet sandal-wearer and secret muesli-chomper, will rip into him instead.

"Objectively", as the Marxists used to say, you might think Labour, therefore, ought to hope AV fails. That would produce the maximum discomfort inside the coalition and lead to the best chance of the government failing to make it to 2015. Some of the anti-AV Labour people covertly make just this point.

The trouble is that if the Tories are able to slash the number of Commons seats while holding off a modest reform to the electoral system, they will be giving themselves a huge boost in the future. That form of manipulation is not something Labour can sit back and allow to happen, for the dubious benefit of causing short-term embarrassment to Clegg. AV might not be the most exciting or indeed proportional system in the world, but without it the prospects for both Labour and the Lib Dems are much bleaker. All the parties know it, which is why the campaigners feel they are playing for high stakes and why so much mud is being hurled.

If the polls are right, the likeliest result is that Cameron will be greatly strengthened by next month's voting. They suggest AV will be defeated and that the SNP will struggle on as a minority administration in Scotland, with some gentle Tory backing. The Lib Dems will be slaughtered at local level but lacking an obvious exit route, will stay unhappily in their Westminster coalition. The big money backing the "No to AV" campaign will quietly chuckle, and complaints about a "rigged" result will mysteriously die away.

Longer term, the smaller Commons elected by first-past-the-post gives the Tories their best chance of coming back with an overall majority next time. The Lib Dems will stagger away to have a nervous breakdown in the comfort of their own telephone box. British politics will return to its familiar and Conservative-biased traditions.

That is what is likely to happen. It is not inevitable. Labour may make it in Scotland and start to open the door to change across the UK. If so, Lib Dems will stare in the mirror and ask, yet again, who they really are. Cameron's strategy of allowing Clegg to pacify his party critics by alarming Tory voters over crime, immigration and university access would begin to unravel as the Tory right bites back. In short, politics would start to look very interesting indeed. AV is fairly dull. Its consequences, though, are spectacular.